Hi , I wish to do some extension to my current attic (2.5 storey) and make it cosy. Currently it is abt 112 sqft and wish to extend out (abt half of 112sqft), add a small toilet (just a toilet bowl and basin), and increase the attic height (now is abt 2m , maybe to 2.5m) Any good contractor to recommend? Any estimation of the cost?